Faecal microorganisms in run-off from cattle farming

Summary

Numbers of faecal microbes (faecal coliforms, enterococci, sulphite-reducing clostridia and coliphages) were determined in run-off waters from cattle farms in 1998-2005. Water samples were collected from drain wells and open ditches adjacent to exercise yards and forested feedlots for cattle, a grass field with slurry applications and a pasture with buffer strips. The indicator numbers were the highest in run-off waters from asphalt exercise yards while the figures were even 100-fold smaller in waters from a bark covered yard. In the forested feedlots, where cattle were fed for the winter months or all the year round, the indicator numbers were as high as the ones in a grass field with slurry applications or a pasture. There was a severe risk of transporting pathogens to the environment, especially if run-off water from exercise yards and feedlots are only poor purifed and allowed to flow into ditches and watercourses. The existence of buffer strips between fields and watercourses may reduce the numbers of faecal microbes in surface run-off.